The present invention relates to a fluidic device.
In liquid chromatography, a fluidic sample and an eluent (liquid mobile phase) may be pumped through conduits and a column in which separation of sample components takes place. The column may comprise a material which is capable of separating different components of the fluidic analyte. Such a material, so-called beads which may comprise silica gel, may be filled into a column tube which may be connected to other elements (like a control unit, containers including sample and/or buffers) by conduits.
When a fluidic sample is pumped through a cylindrical capillary, the Hagen-Poiseuille effect results in a non-uniform velocity profile along a cross-section of the cylindrical capillary and hence of the fluidic sample. Hagen-Poiseuille's law is a physical law concerning the voluminal laminar stationary flow of a viscous liquid through a cylindrical tube with constant circular cross-section. The said non-uniform velocity distribution over the conduit cross-section may result in longitudinal spreading of the zone containing analytes and thus in an undesired deterioration of the separation performance due to band broadening of different fractions of a separated sample.
Knitted Open Tubular reactors are designed to provide an efficient reagent mixing and/or a reaction delay in liquid chromatographic post-column reactions, while preserving the bandwidth of the separated peaks (see http://www.sequant.com/default.asp?ML=11513).
H. Engelhardt, U. D. Neue, “Reaction Detector with Three Dimensional Coiled Open Tubes in HPLC”, 1982 Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, pp. 403-408 discloses a reaction detector with non-segmented flow in open tubes as reaction track. To minimize peak broadening, the open tubes are arranged in a three dimensional coiled structure by knitting.
U.S. Pat. No. 5,032,283 discloses a fluid conduit including a three-dimensional tube having a two-dimensional serpentine opening therethrough and exhibiting low peak dispersion which is applicable as an extra-column connection. The serpentine is a continuously curving path having periodic peaks and valleys of substantially uniform amplitude.
However, dispersion effects may still limit performance of fluidic measurement devices which are to be manufactured with a reasonable effort and in a reasonably small dimension.